#include <u.h>#include <libc.h>#include <ctype.h> char*strupr(char *s){	char *p; 	for(p = s; *p; p++)		if(*p >= 0 && islower(*p))			*p = toupper(*p);	return s;} char*strlwr(char *s){	char *p; 	for(p = s; *p; p++)		if(*p >= 0 && isupper(*p))			*p = tolower(*p);	return s;}